The present invention relates to an electromagnetic injector for internal combustion engine fuel injection systems.
Injectors of the aforementioned type normally comprise a hollow body with a nozzle, which is opened for injecting the fuel by an electromagnetically-operated control valve for connecting the control chamber of the nozzle to the drain conduit.
On known injectors, the electromagnet comprises a magnetic core having an axial conduit communicating with the drain conduit, which is in one piece with a flange cap supporting the core. The hollow body is fitted inside with a bush having a shoulder on which the surface of the core rests, and a ring pressed on to the cap for connecting the cap to the core and looking the core on to the shoulder.
Locking the core on to a rigid shoulder by means of the above pressing operation presents a number of drawbacks. Foremost of these is possible cracking of the core due to the poor mechanical resistance of the sintered magnetic material of which it is made. Moreover, a similar connection tends to eventually work loose, thus resulting in vibration of the core between the shoulder and flange and relatively short working life of the core.